From: Leon Hwang <leon.hwang@linux.dev> mainline inclusion from mainline-v6.12-rc1 commit 7559a7a84ef83a2dd86caf623430b8d834843cec category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBIADD CVE: CVE-2024-47794 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Add a selftest to confirm the issue, which gets -EINVAL when update attached freplace prog to prog_array map, has been fixed. cd tools/testing/selftests/bpf; ./test_progs -t tailcalls 328/25 tailcalls/tailcall_freplace:OK 328 tailcalls:OK Summary: 1/25 PASSED, 0 SKIPPED, 0 FAILED Acked-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Link: https://lore.kernel.org/r/20240728114612.48486-3-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> Conflicts: tools/testing/selftests/bpf/prog_tests/tailcalls.c [The conflict is due to we did not backport b83b936f3e9a testcases] Signed-off-by: Tengda Wu <wutengda2@huawei.com> --- .../selftests/bpf/prog_tests/tailcalls.c | 64 +++++++++++++++++++ .../selftests/bpf/progs/tailcall_freplace.c | 23 +++++++ .../testing/selftests/bpf/progs/tc_bpf2bpf.c | 22 +++++++ 3 files changed, 109 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/tailcall_freplace.c create mode 100644 tools/testing/selftests/bpf/progs/tc_bpf2bpf.c diff --git a/tools/testing/selftests/bpf/prog_tests/tailcalls.c b/tools/testing/selftests/bpf/prog_tests/tailcalls.c index 09c189761926..9e5f0f31e805 100644 --- a/tools/testing/selftests/bpf/prog_tests/tailcalls.c +++ b/tools/testing/selftests/bpf/prog_tests/tailcalls.c @@ -1,6 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 #include <test_progs.h> #include <network_helpers.h> +#include "tailcall_freplace.skel.h" +#include "tc_bpf2bpf.skel.h" /* test_tailcall_1 checks basic functionality by patching multiple locations * in a single program for a single tail call slot with nop->jmp, jmp->nop @@ -884,6 +886,66 @@ static void test_tailcall_bpf2bpf_6(void) tailcall_bpf2bpf6__destroy(obj); } +/* test_tailcall_freplace checks that the attached freplace prog is OK to + * update the prog_array map. + */ +static void test_tailcall_freplace(void) +{ + struct tailcall_freplace *freplace_skel = NULL; + struct bpf_link *freplace_link = NULL; + struct bpf_program *freplace_prog; + struct tc_bpf2bpf *tc_skel = NULL; + int prog_fd, map_fd; + char buff[128] = {}; + int err, key; + + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = buff, + .data_size_in = sizeof(buff), + .repeat = 1, + ); + + freplace_skel = tailcall_freplace__open(); + if (!ASSERT_OK_PTR(freplace_skel, "tailcall_freplace__open")) + return; + + tc_skel = tc_bpf2bpf__open_and_load(); + if (!ASSERT_OK_PTR(tc_skel, "tc_bpf2bpf__open_and_load")) + goto out; + + prog_fd = bpf_program__fd(tc_skel->progs.entry_tc); + freplace_prog = freplace_skel->progs.entry_freplace; + err = bpf_program__set_attach_target(freplace_prog, prog_fd, "subprog"); + if (!ASSERT_OK(err, "set_attach_target")) + goto out; + + err = tailcall_freplace__load(freplace_skel); + if (!ASSERT_OK(err, "tailcall_freplace__load")) + goto out; + + freplace_link = bpf_program__attach_freplace(freplace_prog, prog_fd, + "subprog"); + if (!ASSERT_OK_PTR(freplace_link, "attach_freplace")) + goto out; + + map_fd = bpf_map__fd(freplace_skel->maps.jmp_table); + prog_fd = bpf_program__fd(freplace_prog); + key = 0; + err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY); + if (!ASSERT_OK(err, "update jmp_table")) + goto out; + + prog_fd = bpf_program__fd(tc_skel->progs.entry_tc); + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, 34, "test_run retval"); + +out: + bpf_link__destroy(freplace_link); + tc_bpf2bpf__destroy(tc_skel); + tailcall_freplace__destroy(freplace_skel); +} + void test_tailcalls(void) { if (test__start_subtest("tailcall_1")) @@ -910,4 +972,6 @@ void test_tailcalls(void) test_tailcall_bpf2bpf_4(true); if (test__start_subtest("tailcall_bpf2bpf_6")) test_tailcall_bpf2bpf_6(); + if (test__start_subtest("tailcall_freplace")) + test_tailcall_freplace(); } diff --git a/tools/testing/selftests/bpf/progs/tailcall_freplace.c b/tools/testing/selftests/bpf/progs/tailcall_freplace.c new file mode 100644 index 000000000000..6713b809df44 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/tailcall_freplace.c @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> + +struct { + __uint(type, BPF_MAP_TYPE_PROG_ARRAY); + __uint(max_entries, 1); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(__u32)); +} jmp_table SEC(".maps"); + +int count = 0; + +SEC("freplace") +int entry_freplace(struct __sk_buff *skb) +{ + count++; + bpf_tail_call_static(skb, &jmp_table, 0); + return count; +} + +char __license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c b/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c new file mode 100644 index 000000000000..8a0632c37839 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/tc_bpf2bpf.c @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include "bpf_misc.h" + +__noinline +int subprog(struct __sk_buff *skb) +{ + int ret = 1; + + __sink(ret); + return ret; +} + +SEC("tc") +int entry_tc(struct __sk_buff *skb) +{ + return subprog(skb); +} + +char __license[] SEC("license") = "GPL"; -- 2.34.1